if [ -f test.sh ]; then
	echo "test.sh exist!"
elif [ ! -f test.sh ]; then
	echo "test.sh not exist!"
else
	echo "never happened there"
fi

if test -f test.sh; then
	echo "test.sh exist!"
fi

if [[ -f test.sh ]]; then
	echo "test.sh exist!"
fi

if [ -d Desktop ]; then
	echo "Desktop directory exist!"
fi

echo "over"
